Room temperature curing organopolysiloxanes

ABSTRACT

THE INVENTION RELATES TO CURABLE ORGANOPOLYSILOXANE COMPOSITONS COMPRISING AN ORGANOPOLYSILOXANE AND A DISILAORGANIC CROSS-LINKING AGENT CONTAINING FUNCTIONAL GROUPS WHICH AREHYDROLYZABLE INTHE PRESENCE OF AMBIENT MOISTURE.

United States Patent US. Cl. 260-48 S 5 Claims ABSTRACT OF THE DISCLOSURE The invention relates to curable organopolysiloxane compositions comprising an organopolysiloxane and a disilaorganic cross-linking agent containing functional groups which are hydrolyzable in the presence of ambient moisture.

This application is a continuation-in-part of application Ser. No. 688,336,. filed Dec. 6, 1967 now abandoned.

This invention relates to organopolysiloxanes, particularly organopolysiloxane compositions which are curable at room temperature and more particularly to organopolysiloxane compositions containing novel cross-linking agents and to a method for preparing the same.

Heretofore, it was known that certain fluid organopolysiloxanes when exposed to atmospheric moisture at room temperature are converted to an elastomeric state. The desirability of room temperature curing systems is well known; however, the conventional room temperature curing systems involve two or more stable components which, when mixed together, rapidly cure to a solid workable state. In other words, the end-user was provided with a two-package system in which one component had to be added just prior to use. Although the two-package is adequate (for many applications, there are other applications where the two-package system is not desirable because of the lack of skill of the workmen or because of equipment which is inadequate to carry out the necessary mixing operation.

Consequently, there was a need in the silicone industry for a one-package room temperature curing system which was provided by the introduction of linear polysiloxanes the cross-linking ability of the polymers employed. Still having terminal hydrolyzable functional groups. While these single component room temperature curing compositions have met with commercial success, it has been extremely difficult to adapt them to some circumstances where extended working time is necessary or desirable. Also, in some commercial applications, it is desirable to provide an organopolysiloxane elastomer which is resistant to compression, has greater solvent resistance, improved cross-linking and improved hardness. Heretofore, none of the organopolysiloxanes commercially available provide all of these desirable properties.

'It is therefore an object of this invention to provide an organopolysiloxane which is curable at room temperature. Another object of this invention is to provide compositions which vary in working time without reducing the cross-lining ability of the polymers employed. Still another object of this invention is to provide a curable organopolysiloxane having improved physical properties. A further object of this invention is to provide novel 3,66 1,816 Patented May 9, 1 972 cross-linking agents which will react with hydroxyl-terminated organopolysiloxanes to form an elastomeric material. A still further object of this invention is to provide an organopolysiloxane composition which may be dispensed in a single package.

The foregoing objects and others which will become apparent from the following description are accomplished in accordance with this invention, generally speaking, by providing curable compositions of the general formula:

in which the R(s) which may be the same or ditferent represent monovalent hydrocarbon radicals, halogenated monovalent hydrocarbon radicals or c-yanoalkyl radicals;

R represents monovalent hydrocarbon radicals, halogen ated monovalent hydrocarbon radicals, cyanoalkyl radicals or hydrogen; R is a divalent hydrocarbon radical or a halogenated divalent hydrocarbon radical; R is a di-' valent hydrocarbon radical; R"" is a polymeric organic radical linked to R' by a carbon-to-carbon linkage; Z is a radical hydrolyzable by ambient moisture; m is an integer of at least 1; n is an integer of from 0 to 3 and the sum of m and n is greater than 2 and when Z is an acyloxy radical, m is equal to at least 2 and n is at least 1; x is an integer of from 0 to 20,000 and y is an integer of from 1 to 500. v

The organopolysiloxanes of this invention are prepared by reacting disilaalkanes or -arenes of the formula:

. with an organopolysiloxane of the formula:

i i HO SiO SiO -H RI!!! y wherein R, R, R", R, -R Z, m, n, x and y are the same as those represented above. R and R'are organic radicals selected from the class consisting of alkyl radicals having from 1 to 18 carbon atoms such as methyl, ethyl,-

yl, tetrachlorophenyl, difiuorophenyl and the like; alkenyl radicals such as vinyl, allyl and the like; R" are divalent hydrocarbon or halogenated hydrocarbon radicals having from 2 to 18 carbon atoms such as methylene, ethylene,

propylene, tetramethylene, hexamethylene, octarnethylene, decamethylene, phenylene, phenylethylene, diphenylmethylene and the like. The group represented by R" is a divalent radical having from 1 to 8carbon atoms such as methylene, ethylene, propylene, butylene, hexylene and octylene. R"" are polymers or copolymers which are linked to an organopolysiloxane backbone through a carbon-to-carbon linkage with a divalent hydrocarbon represented by R' above. Z represents groups which are hydrolyzable -by ambient moisture such as.

radicals wherein R and R which may be the same or different represent monovalent hydrocarbon radicals and halogenated mouovalent hydrocarbon radicals and r is a number of from 1 to 2. Examples of suitable hydrolyzable groups are monoacyl radicals of carboxylic acids such as formyloxy, acetoxy, propionyloxy, valeryloxy, caproyloxy, myristoyloxy and stearoyloxy radicals; hydro carbonoxy groups having from 1 to carbon atoms such as methoxy, ethoxy, butoxy, heptoxy, octoxy, decoxy, phenoxy andthe like; aminooxy groups such as dimethylaminooxy, diethylaminooxy, dipropylaminooxy, dibutylaminooxy, dioctylaminooxy, diphenylaminooxy, ethylmethylaminooxy, methylphenylaminooxy and the like. Other hydrolyzable groups are amino, methyl amino, propyl amino, butyl amino, hexyl amino and phenyl amino radicals; oximo radicals such as acetophenone oximo, acetoximo, benzophenone oximo, Z-butanone oximo, diisopropylketone oximo, chlorocyclohexanone oximo, alphabromoacetophenone oximo and the like and phosphato radicals "such as dimethylphosphato, diethylphosphato, dipropylphosphato, dibutylphosphato, dihexylphosphato, dioctylphosphato, didodecylphosphato, dioctadecylphosphato, 'methylethylphosphato, ethylpropylphosphato, methylhexylphosphato, butylhexylphosphato, methyldodecylphosphato, methyloctadecylphosphato, ethyltetradecylphosphato, diphenylphosphato, methylphenylphosphato, butylphenylphosphato and the like. v I

The cross-linking agents of this invention have functional groups which are hydrolyzable by amibent moisture and may be prepared by reacting unsaturated hydrocarbon or unsaturated halogenated hydrocarbon groups with a silane or a halosilane to form the corresponding halodisilaalkanes or -arenes having halogen groups linked to the silicon atoms.

The disilaorganic compounds contemplated in this inventionmay be represented by the following general formula:

whereinR' and R" are the same as those described above and X is a halogen. These compounds may be reacted with compounds containing hydrolyzable groups to provide a composition which is curable in the presence of ambient moisture. For example, the reaction of 3,3-dichloro-3-silabutene-1 with trichlorosilane in the presence of a catalyst'such as chloroplatinic acid, organic peroxides, metal carbonyls and thelike which promote the addition of the silane moiety to an olefinic double bond forms 1,1,1, 4,4-pcntachloro-l,4-disilapentane in accordance with the following equation:

' 31 c1 CH;-Si-CH=CH2 HSiCl CH -SiiCHzCHaSi-Cl l l i Reaction of the above pentachlorodisilapentane with an anhydride, e.g. acetic anhydride, results in the substitution of acetoxy groups for the chlorine atoms which are hydrolyzable with ambient moisture.

In preparing disilaalkanes or disilaarenes having acyloxy functional groups, the halogen containing disilaorganic compounds are reacted with organic acids or anhydrides thereof at a temperature of from about 25 to about 150 C., preferably from about 50 to 120 C. and if desired in the presence of a solvent. Suitable solvents include aliphatic hydrocarbons such as pentane, hexane, heptane, octane; aromatic hydrocarbons such as benzene, toluene, xylene, naphthylene as well as halogenated solvents such as methylene chloride, chlorobenzene and the like. Other solvents which may be used are organic ethers such as petroleum ether, diethyl, dibutyl ether and hydroxyl-free fluid siloxanes.

In the formation of aminooxydisilaalkanes or -arenes an organohydroxylamine is reacted with a .halogen containing disilaorganic compound, preferably in the presence of an inert solvent such as chloroform, benzene, toluene, xylene, perchloroethylene, etc. at a temperature of from about 50 to 60 C. to form the corresponding aminooxydisilaorganic compound. Generally, the reaction is completed in a matter of from about 1 to 2 hours.

Disilaorganic compounds having phosphato functional groups may be prepared by reacting halogen containing disilaorganic compounds with phosphoric acid or an alkali metal or alkaline earth metal salt of an organic phosphate and if desired, in the presence of an inert solvent.

Likewise these halogen-containing disilaorganic compounds may be reacted with amines or carbonoxy contain ing COmpounds to providea composition which is curable inthe presence of atmospheric moisture.

Grafted organopolysiloxanes contemplated in this invention contain an organosilicon polymer backbone having attached thereto at least 1 or more side chains or branches consisting of a carbon chain polymer. In the grafting step, the hydrogen is abstracted from the organosilicone polymer backbone by a free radical initiator to form an active site for the connecting polymer.

Any organopolysiloxane may be used as the backbone polymer in this invention, providing they are capable of producing free radical or active sites under the proper conditions. Thus, the backbone polymer should be one which is capable of producing a substantial and recognizable number of free radicals and it should be substantially free of any tendency to undergo any rfurther polymerization under the conditions employed. Thus, the backbone polymer should be one which is substantially free of any aliphatic unsaturation; however, a low degree of any such unsaturation does not preclude the desired reaction, even though it may set up a competitive reaction which is usually preferably avoided. It is preferred that the organopolysiloxane have lower alkyl radicals attached to the silicon atoms, since these are more amenable to' hydrogen abstraction than other radicals. In addition, it is generally advisable to use organopolysiloxanes substantially free of silicon bonded hydrogen.

Examples of suitable organopolysiloxane polymers and copolymers which may be used in the formation of grafted polymers are hydroxyl-terminated siloxane fluids (OH- fluids) having methyl, phenyl or methylvinyl groups and copolymers of dimethylsiloxane and phenylmethyl or diphenylsiloxane units.

Any polymerizable organic monomer having aliphatic olefinic bonds may be grafted to the organopolysiloxane backbone. Examples of suitable olefinic compounds are low molecular weight straight-chained hydrocarbons such as ethylene, propylene, butylene, vinyl halides such as vinyl chloride and vinyl fluoride; vinyl esters of organic acids such as vinyl acetate; styrene, ring-substituted styrenes and other vinyl aromatics such as vinyl pyridine and vinyl naphthylene; acrylic acid and derivatives of acrylic acid including the salts, esters, amides and acrylonitrile; n-vinyl compounds such as n-vinyl carbazole, n-vinyl pyrrolidone and n-vinyl caprolactam and vinyl silicon compounds such as vinyl triethoxysilane.

Di-substituted ethylenes of the type CH =CX may be used including vinylidene fluoride, vinylidene chloride, vinylidene cyanide, methacrylic acid and compounds derived therefrom such as their salts, esters and amides as well as rnethacrolein, methacrylonitrile and the like.

Examples of di-substituted ethylenes of the type CHX= CHX such as vinylene carbonate and various monomers which polymerize best in the presence of other monomers, e.g. maleic anhydride, estersof maleic and fumeric acids, stilbene, indene and coumerone may be used in the formation of these graft polymers.

As before emphasized, the monomers may be used singly or in combination of two or three or even more. The properties of the graft product, of course, depend on the nature and identity of the monomer material as well as on the amounts used relative to the organopolysiloxanes.

The grafting operation is most expeditiously effected by using a free radical initiator, normally organic peroxides, although other free radical initiators such as azo compounds in which both the N atoms of the azo linkage are attached to a tertiary-carbon atom and the remaining valences of the tertiary carbon atom are satisfied by nitrile, carboxyalkyl, cycloalkylene or alkyl radicals, preferably having from 1 to 18 carbon atoms. In addition to the above mentioned initiators, ionized radiation may also be used to bring about the formation of free radicals.

' The amount of free radical initiator used is not critical. Thus, any amount capable of producing a preceptable degree of grafting is suitable. Generally, as low as 0.05 percent of the more active peroxide initiators based on the weight of the monomer is adequate in most cases. However, where it is desirable to increase the reaction rate, then as much as 3 percent or even more ofthe initiator may be used.

The grafting step may be carried out at a temperature between about 25 and about 150 C., preferably between about 60 and 130 C. in the presence of the free radical initiators. Where the reaction is carried out in the absence of these initiators, a substantially higher temperature, often as high as 200 C., may be advantageously used.

Although the grafting step may be conducted in the presence of an inert solvent, that is, a solvent which is unreactive to the monomer or the organopolysiloxane in the presence of a free radical initiator, it is preferred that the grafting step be conducted in the absence of a solvent. Examples of solvents which may be employed Where desired are hexane, heptane, benzene, toluene, xylene, naphthalene and the like.

Although it may be possible to carry out the grafting procedure using organopolysiloxanes free of terminalhydroxyl groups or groups hydrolyzable by ambient moisture and to subsequently treat the grafted polymer to incorporate such groups, it is preferred in the grafting operation to use an organopolysiloxane having terminalhydroxyl groups. Following this procedure, the graft polymer is appropriately treated to substitute groups which are hydrolyzable by ambient moisture for the hydroxyl groups.

The grafted products may be separated from the unrecure.

acted monomers by any conventional technique known in the art such as by distillation, solvent extraction or selective solvent fractionation.

The curable organopolysiloxane compositions of this invention may be prepared by reacting the disilaalkanes or -arenes containing hydrolyzable groups at ambient moisture with the organopolysiloxanes at any convenient temperature. Although, in general, temperatures ranging from about 20 to C. are suflicient. It should be understood, of course, that higher or lower temperatures may be employed if desired although, preferably the reaction should be carried out at temperatures below about 200 C.

If desired, the reaction may be carried out in the presence of an inert solvent which is unreactive with both the terminal hydroxyl groups on the organopolysiloxane or the functional groups on the disilaalkanes or disila'arenes. Solvents which may be used include hydrocarbons such as benzene, toluene, xylene; halogenated solvents such as ethylene chloride, perchloroethylene, chlorobenzene and the like; organic ethers such as diethyl ether, dibutyl ether and hydroxyl free fiuid siloxanes. The presence of solvents are'particularly desirable when the hydroxyl-terminated organopolysiloxane has a high viscosity. In these cases, the presence of a solvent reduces the overall viscosity of the mixture and facilitates the reaction.

The ratio of the disilaorganic cross-linking agent to the organopolysiloxane is not critical; however, it is preferred that at least one mole of the disilaorganic cross-linking agent be used per mole of silicon bonded hydroxyl group and more preferably from about 2 to 5 moles of the disilaorganic crosS-linking agent be used per mole of silicon bonded hydroxyl group in the organopolysiloxane. It is possible to use up to about 12 moles of the disilaorganic cross-linking agent per mole of silicon bonded hydroxyl group in the siloxane. A large excess of the cross-linking agent containing functional groups insures complete reaction with all silicon bonded hydroxyl groups and in addition, acts as a scavenger for any moisture which may be present. It is preferred that the reaction be carried out in the absence of moisture since the latter may interfere with the reaction. However, traces of moisture are not especially harmful if an excess of the disilaorganic cross-linking agent is used.

The compositions of this invention may be cured by merely exposing them to atmospheric moisture with or without any additional water vapor. Upon exposure to moisture, the compositions cure in times from a few minutes to several hours or days depending upon the type of groups present. In general, an increase in the molecular weight of any of the groups will increase the time of the Where it is desirable to modify the consistency of the uncured composition or to reinforce the cured products or for some other purpose, mineral fillers in the form of very fine powders may be incorporated therein.

Examples of mineral fillers which may be used are various kinds of silicas, oxides of iron, zinc, cadmium, aluminum and carbonates. The particular filler and proportion in which it is used will depend to a certain extent on the particular use to which the composition is to be applied.

- Silica obtained by precipitation, for example, those sold under the trade names Santocel and Hi-Sil and silicas obtained from combustion such as sold under the trade name Aerosil, are particularly suitable for the production of reinforced elastomeric products. These silicas are microfine products having a large absorptive surface and are very effective even in small quantities. Fillers such as milled natural silicas and calcium carbonate can, on the other hand, be employed in large proportions, for example, 100 percent based on the weight of the organopolysiloxane.

Apart from the fillers mentioned heretofore, compositions conforming to the invention may contain coloring agents, thixotropic agents, agents capable of preventing the passage of ultraviolet light, desiccants and antioxidants.

These compositions may be dissolved or dispersed in organic diluents which are compatible with the organopolysiloxanes. Examples of suitable diluents. are aromatic hydrocarbons such as benzene, toluene or xylene; .aliphatic hydrocarbons such as hexane and heptane and halogenated aliphatic hydrocarbons such as methylene chloride and the like.

In addition to the constituents mentioned above, the compositions of this invention may contain for the purpose of accelerating the curing rate, certain compounds which have a catalytic eflect on the condensation reactions, Although several compounds are known to have a catalytic eflect on the curing rate, organotin compounds were found to be the most desirable. Examples of suitable catalysts are the tin salts of organic acids such as tin naphthenate, tin-Z-ethylhexanoate, tin benzoate, dibutyltin dilaurate, dibutyltin diacetate, bis (dibutyltin oleate)oxide, bis(dibutyltin stearate)oxide, dibutyltin oleate hydroxide and the like. These tin compounds may be used in an amount determined as tin metal of from 0.001 to about 1 percent by weight based on the weight of the organopolysiloxanes.

It is preferred that a catalyst, particularly a tin salt of an organic acid be incorporated in curable orgauopolysiloxane compositions containing oximo functional groups in order to obtain a satisfactory curing rate when exposed to ambient moisture. As mentioned previously, the catalyst may be used in compositions containing other functional groups where it is desirable to increase cure rate for a specific application.

The compositions of this invention may be prepared by mixing liquid hydroxyl-terminated organopolysiloxanesv and a filler in any conventional mixing apparatus such as a Sigma Blade mixer, roller mill, Banbury mixer and the like; and thereafter heating the mixture for a suflicient time to eliminate all traces of moisture. The mass is then cooled and the disilaorganic cross-linking agent containing functional groups is added and if desired, a catalyst and an anhydrous organic diluent. The composition may be used immediately or it may be transferred under anhydrous conditions to dry containers which are then hermetically sealed. The products thus prepared may be kept -for several months-and even years.

These compositions are stable in the absence of moisture, consequently they may be stored for prolonged periods of time with little or no change occuring'in the physical properties of the composition. This is of particular importance from a commercial stand-point since it assures that once a composition is prepared having a certain consistency and cure time that neither will change to any great extent upon storage. This stability on storage is a characteristic which makes the composition of this invention particularly useful as one-component room temperature curing compositions.

Also, the disilaorganic compounds, especially those having at least four acyloxy groups linked to the molecule, may be used as primers on metal, Wood, glass, ceramic and masonry substrates for room temperature curing oneand two-component grafted and ungrafted organopolysiloxanes. The primer may be applied by brushing, spraying or dipping by itself or in solution. Where it is applied as a solvent solution, it is preferred that the solvent portion be not greater than about 25 percent by weight of the primer composition.

The drying rate of the primer is primarily dependent on two factors. One factor is the rate of condensation of the disilaorganic compound or partial hydrolyzates thereof" which is dependent first, on the size of the R and'acyloxy radicals and second, on the amount of waterpresent for' hydrolysis of the acyloxy radicals to volatile acids. Where R and the acyloxy radicals are large, the rate of hydrolysis and condensation of the disilaorganic compound is very 7 The other factor is the presence or absence of solvent. If a solvent is employed, the volatility of the solvent affects the drying rate of the primer, therefore, it is desirable that any solvent employed be sufiiciently volatile to evaporize under coating conditions at least as rapidly as the disilaorganic compound can hydrolyze and condense.

The curable organopolysiloxanes of this invention ad here to a variety of materials such as, for example, wood, metal, glass, ceramics, plastics and the like. In the case of metals, it may be desirable to apply an appropriate pretreatment to the metal before applying the composition of this invention. These self-curing compositions may serve for caulking, covering various articles such as electrical equipment, coating glass, metals, fabrics, protecting various supports and producing films and molded articles. These compositions may be applied by any of the usual techniques such as by dippin doctoring or spraying.

Various aspects of the invention are further illustrated by the following examples which are not to be taken'as in any way limiting the scope thereof. In the example, all parts are by weight unless otherwise specified.

EXAMPLE 1 about 500 parts of benzene.

To. this mixture are added with agitation over a 30 minute period about 600 parts'of acetic anhydride in about 300 parts of benzene. The reaction mass is refluxed for about 45 minutes at atemperature of about C. The

. volatile materialsare removed in vacuo and a product identified as 1,1,1,4,4-pentaacetoxy-1,4-disilapentane is re-' covered.

Approximately 3 parts of the above prepared penta acetoxydisilapentane are reacted with about 50 parts of a hydroxyl-terminated polysiloxane fluid (2,000 cs.) at

60 C. with agitation for about 0.5 hour in the absence of moisture. The volatile materials are removed by vaccum distillation and the residual product placed in 'a' mold and allowed to cure at room temperature. It cured to a tack-free condition in less than about 2 hours.

EXAMPLE 2 To a reactor fitted with a mechanical agitator, reflux condenser, nitrogen inlet and an addition funnel are added about 384 parts of 2,2,5,S-tetrachloro-2,5-disilahexane in about 400 parts of benzene. About 642 parts of acetic anhydride in about 400 parts of benzene are added dropwise through the addition funnel. The'reaction mass is refluxed at a temperature between and 102 C. for about 2 hours. The volatile materials are'removed under vacuum yielding a product identified as 2,2,5,5-tetra-acetoxy-'2,5 disilahexane. a

To about parts of a hydroxyl-terminated-'polydimethylsiloxane (2,000 cs.) are added with mixing in' the absence of moisture about 15 parts of Gab-O-Sil and about 15' parts of the tetra-acetoxydisilahexane prepared above. After mixing for about /2 hour, the volatile-materials are removed under vacuum and theresidual product transferred to a mold and'allowed to cureat room tempera ture. The product cured to a tack-free condition in about 1.5 hours.-

- EXAMPLE 3 In accordance with the procedure -described in Example '2', about 490 parts of acetic anhydride in about 300 parts of benzene are added to a reactor containing about" 312 parts of 2,2,7,7-tetrachloro-2,7-disilaoctane in about 500 parts-of benzene. The reaction mass isrefluxed at about 100 C. for about 2 hours. The volatile materials are then removed under vacuum yielding a product identified as 2,2,7,7-tetra-acetoxy-2,7sdisilaoctane.

9 EXAMPLE 4 In accordance with the procedure described in Example 2, approximately 490 parts of acetic anhydride are added dropwise to a reactor containing about 424 parts of 2,2, 11,1l-tetrachloro-2,1l-disiladodecane. The reaction mass is refluxed for a period of about 2.5 hours and the volatile materials are then removed under vacuum. A product is recovered which is identified as 2,2,l1,ll-tetra-acetoxy-Z, 1 l-disiladodecane.

EXAMPLE 5 In accordance with the procedure described in Example 2, approximately 1,158 parts of decanoic acid are added dropwise to a reactor containing 312 parts of 2,2, 7,7-tetrachloro-2,7-disilaoctane. The reaction mass is refluxed for a period of about 3 hours and the volatile mate? rials are then removed under vacuum. A residual prodnot is recovered which is identified as 2,2,7,7-tetradecanoy1oxy-2,7-disilaoctane.

7 EXAMPLE 6 Inaccordance with the procedure described in Example 1, approximately 731 parts of N,N diethylhydroxylamine dissolved in about 170 parts of dry heptane are added to a reactor containing 235 parts of 1,1,1-trichloro-4,4-dimethyl-1,4-disilapentane in about 250 parts of dry heptane and heated to reflux temperature for about 1 hour. A precipitate is formed which is removed by filtration and identified as N,N-diethylhydroxylamine hydrochloride. The heptane solvent. and excess N,N-diethylhydroxylamine are removed in vacuo yielding a residual product which is identified as 1,1,1-tris(N,N-diethylamino oxy)-4,4-dimethyl-1,4-disilapentane.

EXAMPLE 7 EXAMPLE 8 In accordance with the procedure described in Example 7, approximately 87 parts of 1,1,1 trichloro-12,12-dimethyl-1,12-disilatridecane in about 200 parts of dry heptane are reacted with about 150 parts of N,N-diethylhydroxylamine. The product is recovered which is identified as 1,1,l-tris(N,N-diethylaminooxy) 12,12-dimethyl-l,12- disilatridecane.

' EXAMPLE 9 Approximately 70 partsof 1,1,1,4,4-pentachloro-1,4-disilapentane in about 80 parts of dry heptane are reacted with about 230 parts of N,N-diethylhydroxylamine in about 60 parts of dry heptane for about 1 hour at reflux temperature. A precipitate is formed which is removed by filtration and identified as N,N-diethylhydroxylamine hydrochloride. The heptane solvent and excess N,N-diethylhydroxylamine are removed in vacuo and a residual product is recovered which is identified as l,1,1,4,4-pentakis (N,N-diethylaminooxy)-1,4-disilapentane.

EXAMPLE 10 .In accordance'with the procedure described in Example 9,.approximately 650 parts of N,N-dioctylhydroxylamine dissolved in about 400 parts of dry heptane are added to a reactor containing about 98 parts of l,1,1,12,12-pentachloro-1,12-disilatridecane dissolved in about 100 parts of dry heptane. A residual product is recovered which is identified as 1,1,1,12,12-pentakis(N,N-dioctylaminooxy)-1.12- disilatridecane.

EXAMPLE 11 In accordance with the procedure described in Example 9, about 300 parts of N-butyl-N-ethylhydroxylamine dissolved in about 200 parts of dry heptane are added to a reactor containing about 83 parts of 1,1,1,8,8-pentachloro- 1,8-disilanonane in about 100 parts of dry heptane. A residual product is recovered which is identified as l,l,1,-8,8 pentakis(N-butyl-N-ethylaminooxy) 1,8-disilanonane. 1 r

7 EXAMPLE 12 About 75 parts of acetoxime dissolved in about 357 parts of ethyl ether are added dropwise with stirring to a reactor containing a solution of 50 parts of l,l,l,4,4-pentachloro-1,4-disilapentane dissolved in about 1,200 parts of toluene and about 90 parts of pyridine. As the exothermic reaction progresses, additional toluene is added in small increments to disperse the large volume of pyridine hydrochloride which is formed. After the reaction is complete. the reaction mass is cooled to room temperature. The product mixture is filtered, stripped of toluene and excess pyridine. A residual product is recovered which is identified as:

EXAMPLE 13 In accordance with the procedure described in Example 12, approximately 197 parts of benzophenone oxime dissolved in 350parts of ethyl ether are added dropwise with stirring to a solution of 70 parts of 1,1,1,l2,12-pentachloro- 1,12-disilatridecane in about 1,400 parts of toluene and about 90 parts of pyridine. As the exothermic reaction progresses, additional toluene is added in small increments to disperse the large volume of pyridine hydrochloride thus formed. After the reaction is complete and the reaction mass cooled to room temperature, the product mixture is'filtered, stripped of toluene and excess pyridine The residual product is identified as EXAMPLE 14 Approximately 88 parts of butyraldoxime in about 30 parts of ethyl ether are added dropwise with stirring to a solution of 60 parts of 1,1,1,8,8-pentachloro-1,8-disilanoname in about 1,000 parts of toluene and about 92 parts of pyridine. As the reaction progresses, additional toluene is added in small amounts to disperse the large volume of pyridine hydrochloride formed. After the reaction is complete, it is cooled to room temperature. The reaction mass is filtered, stripped of toluene and excess pyridine. A

-. residual product is recovered which is identified as by chemical analysis.

EXAMPLE 15 fluxed for about 45 minutes and the volatile materials removed invacuo. A product is recovered which is identified as 1,1,1,4,4-pentaacetoxy-1,4-disilapentane by chemical analysis. 7

which is identified as 1,1,1,8,8-pentakis(diphenylphos- 11 EXAMPLE 16 In accordance with the procedure described in Example 15, approximately 172 parts of decanoic acid are reacted. with about 70 parts of 1,l,1,12,12 pentachloro 1,12-

disilatridecane. A residual product is recovered which is identified as1,1,1,12,12 pentadecanoyloxy-1,12-disilatridecane.

EXAMPLE l 7 In accordance with the procedure described in Example 15, approximately 116 parts of hexanoic acid are reacted with about 60 parts of 1,1,1,8,8-pentachloro 1,8-disilano nane. A residual product is recovered which is identified by chemical analysis as 1,1,1,8,8-hexanoyloxy-1,8-disilanonane.

EXAMPLE 18 Approximately 154 parts of diethylhydrogenphosphate are added to about 500 parts of benzene. and introduced into a reactor containing 50 parts of l,1,1,4,4-pentachloro- 1,4-disilapentane in about 250 parts of benzene. The-reactants are heated to reflux temperature for about 0.5 hour with agitation. Nitrogen is then passed through the solution for approximately 4 hours and the solvent and volatile materials are removed under vacuum distillation. A residual product is recovered which is identified as 1,1,1,4,4-pentakis(diethylphosphato)-1,4-disilapentane.

EXAMPLE 19 In accordance with the procedure described in Example 19, approximately 38 parts of dimethylhydrogenphosphate' are reacted with about 24 parts of 1,1,l-trichloro-4,4-dimethyl-1,4-disilapentane. A residual product is recovered which is identified as 1,1,l-tris(dimethylphosphato)-4,4-dimethyl-1,4-disilapentane.

EXAMPLE 21 In accordance with the procedure described in Example 19, approximately 250 parts of diphenylhydrogenphos-, phate are reacted with about 60 parts of- 1,1;1,8,8-pentachloro-1,8-disilanonane. A residual product is recovered phato)-l,8-disilanonane.

EXAMPLE 22 chloro-2,5-disilahexane dissolved in about-l50 parts of benzene are added about 190 parts of N,N-diethylh ydroxylamine dissolved in about 150 parts of benzene and heated to reflux temperature for about 1 hour. A precipitate is formed which is removed by filtration andidenti-- fied as N,N-diethylhydroxylamine hydrochloride. The solvent and excess N,N-diethylhydroxylamine are removed in vacuo yielding a residual product which isidentified as 2,2,5 ,S-tetrakis(N,N-diethylaminooxy)-2,5-disilahexane.' 1

EXAMPLE 23 In accordance with the procedure described in Example 22, approximately 70 parts of 2,2,7,7-tetrachloro-2;7-di

. identified as 12 which is identified as 2,2,7,7-tetrakis(N,N-dioctylarninooxy)-2,7-disilactane.

EXAMPLE 24 In accordance with the procedure described in Example 22, 85 parts of 2,2,11,11-tetrachloro-2,1lrdisilaidodecane are reacted with about 250 parts of N-butyl-N-ethylhy{ droxylamine. A residual product is recovered which is 2,2,1 1,1 l-tetrakis- (N-butyl-N-ethylaminooxy) -2,1 l-disiladodecane.

' EXAMPLE 25 About 80" parts of acetoxime dissolved in about 357 parts of ethyl ether are added dropwise with stirring to'a solution of 60 parts of 2,2,5,5-tetrachloro-2,5-disilahexane in about 1,100 parts of toluene and about 90 partsl o'f, pyridine. As the exothermic reaction progresses, addi{ tional toluene is added in small increments to' disperse the large volume of pyridine hydrochloride formed. After the reaction is complete, the reaction mass is cooled to room temperature and the product mixture filtered, stripped of toluene and excess pyridineanddistilled. A residual product is recovered which is identified by chemical analysis as: I

a 3)2]2 2 V i V. 2 H3)2]2C a EXAMPLE '26 I In accordance with the proceduredescribed in Example 25, about 140. parts of hexanone oxime dissolved in about 200 parts of ethyl ether are added. to a solution of about parts of 2,2,7,7-tetrachloro-2,7-disilaoctane in about 1,100 parts of toluene. A residual product is recovered which is identified by chemical analysis as:

Inaccordance with the procedure described in Example.

25, approximately 150 parts of acetophenone oximein' about 300 parts of diethyl ether are reacted with .about 85 parts of 2,2,11,11-tetrachloro-2,ll-disiladodecane, A

. residual product is recovered which is identified by chemical analysis as:

EXAMPLE 28 To a reactor containing about 66 parts of 2,2,5,'5-tetra-r 1 f. tetragcetqxy'zs'dlsilahexane' EXAMPL 2 f In accordance withthe procedure described i i-Example 28, about 180 parts of decanoic aciddissolved in benzene are added dropwise to a reactor containing about- 70 partsof 2,2,7,7-tetrachloro-2,7edisilaoctane. A residual,

reaction product is recovered .which is identified tetradecanoyloxy-2,7rdisilaoctane.

EXAMPLE 30 In accordance with the procedure described in Example 28, approximately parts of.acetic anhydride dissolved in about parts of ethyl ether are added to a reactor containing about 80'parts of 2,2,11,11-tetrachloro-2,11- disiladodecanedissolved in about 1,100 parts of tolueneg A residuai product is'recovered which is 'identifidzis 2,2,l1,1 1-tetraacetoxy-2,l l-disiladodecane.

13 EXAMPLE 31 When the above examples are repeated utilizing other disilaorganic compounds-with hydroxyl-terminated grafted organopolysiloxanes, elastomeric materials are obtained which have properties substantially equivalent to those of the specified examples.

Although specific examplesof the invention have been described herein,:other-variations and modifications falling within the spirit and scope of the appended claims; are

The pertinent data is illustrated in Table I. 10 tolbe included therein. TABLE I Free-radical Reaction Olefinic compound Hydroxylated fluid initiator conditions lFinal p ymer, Viscosity, Temp, Time, viscosity, Example No. Type Par cs. Parts Type Parts 0. hr. cs.

Acrylonitrile 14. 6 31(8) 2 aqgsqateun g 3 1, 900 50 t-BP o. a so 1. s 14, 000

cry om r1 e Bum acrymen 5L 0 s00 40 t-BP o. 5 so 1. 7 7, s00 Aerylonitrile--.- 9. 1 31(0) Ethyl acrylate to) 800 40 -131 0. 80 2. 0 20, 200 60. 0 400 50 t-BP 0. 5 80 4. 0 15, 500 70. 0 400 t-BP 0. 5 80 5. 0 19, 400 332:8 e10 304 t-BP 2. 0 125 2A. 0 14, 500 31(g) Vinyl chloride 45. 0 6, 700 350 t-BPer 1. 8 80 4. 0 17, 800

N o'rE.t-BP=tertiary butyl peroxide. t-BPer= tertiary butyl peroctoate.

EXAMPLE 32 The invention claimed is:

A reactor containing approximately 31.3 parts of a grafted hydroxyl-terminated organopolysiloxane prepared in accordance with the procedure described in Example 3:l(a) is evacuated for about 10 minutes. About 3 parts of the cross-linking agent prepared in accordance with the procedure described in Example 1 are added to the reactor and the reaction mass is heated to a temperature of about 80 C. with agitation. After about 1 hour, the volatile materials are removed by vacuum distillation and the residual product placed in a mold and allowed to cure at room temperature. It cured to a tack-free condition in less than 2 hours yielding an elastomeric solid.

EXAMPLES 3 3-49 In accordance with the procedure described in Example 32, organopolysiloxanes are reacted with various cross-linking agents and curedat room temperautre at ambient moisture. The compositions cured to a tack-free condition in a period of time ranging from about 0.4 to about 6 hours. In some of the following examples, fillers are added to improve the physical properties. The results of these experiments are illustrated in Table 11.

Norn .DBTD=dibutyltin dilaurate. DBTO=bis (dibutyltin oleate) 1. A composition curable to an elastomeric solid when exposed to atmospheric moisture at room temperature comprising an organopolysiloxane of the formula:

in which R is selected from the group consisting of monovalent hydrocarbon radicals, halogenated monovalent hydrocarbon radicals and cyanoalkyl radicals; R is selected from the group consisting of hydrogen, monovalent hydrocarbon radicals, halogenated monovalent hydrocarbon radicals and cyanoalkyl radicals; R" is selected from the group consisting of divalent hydrocarbon radicals and halogenated divalent hydrocarbon radicals; R is a divalent hydrocarbon radical; R"" is a polymeric organic side chain linked to R' via an alkylene group, said polymeric organic side chain being constituted of recurring units derived from olefins selected from the class consisting of unsaturated aliphatic hydrocarbons whether or not attached to an aromatic nucleus, halogenated olefins again whether or not attached to an aromatic nucleus, unsaturated acids, esters of organic acids in which either the esterifying group or the derivative acid is unsaturated, unsaturated amides and unsaturated nitriles; Z is a hydrolyzaible group selected from the class consisting of hydrocarbonoxy, aminooxy, amino, oximo, and phosphato radicals; m is a number of at least 1 and up to 3; n is a number of from 0 to 3; the sum of m'and n in each terminal disilaorganic group is greater than '2 and up to 6; x is a number of from 0 to 210,000 and y is a number of from 1 to 500.

2. The composition of claim 1 which contains a tin salt of a carboxylic acid.

3. The composition of claim 1 wherein Z is a phosphato radical. 

